title: Transannular Diels-Alder/1,3-dipolar cycloaddition cascade of 1,3,4-oxadiazoles: total synthesis of a unique set of vinblastine analogues.
abstract: A powerful tandem [4 + 2]/[3 + 2] cycloaddition cascade of 1,3,4-oxadiazoles initiated by a transannular [4 + 2] cycloaddition is detailed. An impressive four rings, four carbon-carbon bonds, and six stereocenters are set on each site of the newly formed central six-membered ring in a cascade thermal reaction that proceeds at temperatures as low as 80 °C. The resulting cycloadducts provide the basis for the synthesis of unique analogues of vinblastine containing metabolically benign deep-seated cyclic modifications at the C3/C4 centers of the vindoline-derived subunit of the natural product.
authors.affiliation: Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
authors.forename: Erica L
authors.initials: EL
authors.lastname: Campbell
authors.forename: Colin K
authors.initials: CK
authors.lastname: Skepper
authors.forename: Kuppusamy
authors.initials: K
authors.lastname: Sankar
authors.forename: Katharine K
authors.initials: KK
authors.lastname: Duncan
authors.forename: Dale L
authors.initials: DL
authors.lastname: Boger
mesh_terms: D003500:Cyclization; D015394:Molecular Structure; D010069:Oxadiazoles / Q000737:chemistry*; D013237:Stereoisomerism; D014747:Vinblastine / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D010069:Oxadiazoles; C583463:1,3,4-oxadiazole; D014747:Vinblastine